1. Field of the Invention
The present invention relates to an inductive displacement detector operative to detect a displacement using magnetic coupling (flux coupling) for use in applications to small measuring tools typically including a caliper and a micrometer, rotary encoders, linear encoders, and sensor instruments.
2. Description of the Related Art
Inductive displacement detectors have been employed to accurately measure a linear displacement or an angular displacement in the art. The detectors are classified into a linear type and a rotary type. The Inductive displacement detector of the linear type comprises a scale including flux coupling windings arranged at a certain pitch; and a sensor head arranged opposite to and movable relative to the scale. The sensor head includes a transmission winding and a receiver winding arranged for flux coupling to the flux coupling windings. This configuration is disclosed in FIG. 1 of JP-A 10/318781, for example. In the inductive displacement detector of the rotary type on the other hand, the transmission winding and the receiver winding are arranged on a stator, and a conductive plate similarly serving as the flux coupling windings is arranged on a rotor. This is disclosed in FIG. 16 of JP-A 8/313295, for example.